Transition To Extrauterine Life

Question 1

What happens to Fetal breathing movements (FBM) as gestation increases?

Answer 1

FBM increase in strength and frequency, occurring up to 80% of teh time in an organised episodic period of ~30 mins coinciding with REM sleep

Question 2

What is the point if fetal breathing movements?

Answer 2

While not involved I.n fetal oxygenation, fetal breathing movements nevertheless have an important role in lung growth and in development of respiratory muscles and neural regulation.

Question 3

What is pulmonary surfactant made up of?

Answer 3

Mixture of lipids, proteins and carbohydrates which s produced by alveolar epithelial cells.

Question 4

What does pulmonary surfactant do?

Answer 4

Is surface active and acts to decrease surface tension at the air-liquid interface of the alveoli
Essentially stops the alveoli collapsing and sticking together when air leaves the lungs.

Question 5

What gestation does pulmonary surfactant increase between?

Answer 5

24-35 weeks.

Question 6

What are the respiratory changes during and after birth?

Answer 6

At birth, the lungs become the primary organs of respiration.
Air replaces fluid as the newborn takes their first breaths.

Question 7

What does mechanical compression of the chest create?

Answer 7

A negative pressure and draws air into the lungs.

Question 8

What happens to the lungs when the newborn cries?

Answer 8

Further expansion and distribution of air throughout the alveoli occurs.

Question 9

What do the lung blood vessels do after the first breath?

Answer 9

Respond to the increase in oxygen content of the blood by dilating and encouraging blood to flow to the lungs.

Question 10

How and what should you look for when assessing respiration in the neonate?

Answer 10

Respiration rate = 40-60bpm.
* However, neonates are periodic breathers rather than regular. breathers so may be periods of even and uneven breathing with long gaps between breaths.
* For first 2-3 months, the baby is an obligatory nose breather and is unable to breathe through mouth.
* Breathing rate more easily observed by observing abdomen as diaphragm/abdominal muscles used for respiratory movement due to immature ribcage and respiratory musculature

Question 11

What are abnormal signs of respiration in the neonate?

Answer 11

tachypnoea at rest, stridor, expiratory grunting, nasal flaring, intercostal and subcostal recession, lack of symmetry.

Question 12

What are the 4 temporary structures involved in fetal circulation that maximise circulation to vital areas?

Answer 12

Ductus Venosus
Foramen Ovale
Ductus Arteriosis
Hypogastric Arteries.

Question 13

What are some cardiovascular adaptations to fetal blood?

Answer 13

Contains larger and more numerous erythrocytes, with a higher haemoglobin content.
Fetal haemoglobin has a higher affinity for oxygen.

Question 14

What does fetal circulation look like?

Answer 14

*Fetus connected to placenta by umbilical cord (2arteries and 1 vein).
* Most of right ventricle output is delivered to placenta for oxygenation.
* Most of left ventricle output delivered to heart, brain and upper part of the body.
* Fetal blood is oxygenated in the placenta and returns to fetus via umbilical vein.
* Oxygenated blood from placenta divides as it enters the liver and shunted through by the ductus venosis.
* It enters inferior vena cava in the heart at the right atrium
* Directed through the foramen ovale into the left atria – to left ventricle via the aorta.
* Blood that drains from the head and arms of the fetus comes in through the superior vena cava and into the right atrium. This blood then goes down to the right ventricle and shoots up the pulmonary trunk to go to the lungs.
* The lungs are non-functional and collapsed, and so the vascular system is highly pressurised, and this pushes blood across to the aorta via the ductus arteriosus.
* This directs blood past the 3 vessels that take blood to the brain of the fetus, and the rest of the blood is sent down the abdominal aorta to the legs, where the 2 umbilical arteries are, and this returns blood back to the placenta for oxygenation. And whole cycle continues

Question 15

How is the formaen Ovale closed?

Answer 15

After birth and taking of the first breath, the atrial pressure is lowered and the left atria pressure increased slightly, causing closure of the foramen ovale at or soon after birth.

Question 16

What is patent foramen ovale (PFO)

Answer 16

A small hole i the heart that doesn’t close after birth. Common and occurs in 20-34% of the population.

Question 17

How does the ductus venosus close?

Answer 17

The cessation of blood flow to the umbilical vein and arteries, initiates functional closure of the ductus venosus within minutes after birth.

Question 18

What is the purpose of the ductus venosus in a fetus?

Answer 18

Shunts a portion of umbilical vein blood flow directly to the inferior vena cava, thus it allows oxygenated blood from the placenta to bypass the liver.

Question 19

What happens to the ductus venosus and hypogastric arteries after birth?

Answer 19

Gradually fibrose and become supporting ligaments.

Question 20

When does the ductus arteriosus close?

Answer 20

Functionally closes at day 4-7, but structural closure can take several months when fibrin is laid down.

Question 21

What happens in the circulatory and respiratory system as a concequence of the first breath?

Answer 21

After first breath – lungs open. Pressure gradients change.
* Left side of heart foramen ovale now closes which separates the right and left atrium.
* Rising Oxygen levels open up the arterioles in the lungs (alveoli).
* Higher Oxygen levels in the blood causes the ductus arteriosus to close.
* Blood with higher Oxygen levels going down to the legs causes the umbilical arteries to obliterate and close.
* Following clamping and cutting of the cord, the remnants of the umbilical vein from naval to liver known as the Terrys ligament will fibrose

Question 22

What is the main function of the neonatal liver?

Answer 22

Considered the central hormone of homeostasis. One of the main functions that the liver must be capable of, is the synthesis of glucuronyl transferase, which is essential for bilirubin conjugation.

Question 23

What does feeding stimulate in the liver?

Answer 23

Stimulates liver function and bacterial colonisation of the gut which in turn stimulates vitamin K production crucial to normal coagulation.

Question 24

What is the bilirubin physiology by Marshall and Raynor 2020?

Answer 24

• Bilirubin – produced as one of the breakdown products of haemoglobin.
• Unwanted RBC removed from circulation and broken down in the reticuloendothelial system of which the liver is part.
• Haemoglobin is broken down into Haem, Globin and Iron.
• Haem is converted to unconjugated bilirubin, a fat-soluble product.
• Unconjugated bilirubin transported to liver bound to albumin, combines with glucose and glucuronic acid, resulting in conjugation, it is now water soluble and can be excreted through urine and faeces.

Question 25

What is our understanding of fetal-newborn glucose metabolism by Thornton and Pulchaslski?

Answer 25

• Healthy infants experience an expected drop in blood glucose concentrations immediately following birth.
• This is part of the normal physiologic transition to extrauterine life.
• Abruptly clamping the umbilical cord at birth disrupts the infant’s connection to the placenta, upon which it relied to supply glucose and other metabolites necessary to meet its energy needs in utero.
• The continuous supply of exogenous intravenous glucose from the placenta suddenly ceases, and the infant’s blood glucose concentration declines in the first hours of life.
• For most healthy infants, this transitional neonatal hypoglycemia is brief, transient and most often asymptomatic

Question 26

When is meconium produced and what is it made up of?

Answer 26

Day 0-2
Meconium (gradually accumulated from16th week of intra-uterine life consists of mucus, epithelial cells, swallowed amniotic fluid, fatty acids and bile pigments)Soft greenish-black viscid/sticky substance like tar. One or more stools a day Indicates that the lower bowel is patent

Question 26

What changes to babys glucose metabolism at birth and when should blood glucose levels rise by?

Answer 26

At birth, the baby has to switch from obtaining glucose fro the mother via the placenta to independent glucose production resulting in an initial drop in blood glucose levels.
Blood glucose should rise at approx 3-4 hours old.

Question 27

What are the characteristics of the GI tract at birth?

Answer 27

• The GI tract at birth is structurally complete, although functionally immature
• The stomach at birth has a small capacity holding only 15-30mls at first
• The cardiac sphincter is weak predisposing to regurgitation of milk
• Gastric emptying is 2-3 hours
• Enzymes are present, although there is a deficiency of amylase and lipase, which reduces the neonate’s capacity to digest compound carbohydrates and fat

Question 27

What happens in the GI tract when milk enters the newborn’s stomach?

Answer 27

A gastrocolic reflux occurs and results in the opening of the ileocaecal valve. The contents of the ileum pass into the large intestine and rapid peristalsis means that feeding is often accompanied by reflux emptying of the bowel.

Question 28

How many wet nappies should there be on day 0-2?

Answer 28

2 or more daily

Question 29

What is the colour and makeup of poo on day 3-4 and how many wet nappies should there be?

Answer 29

• Neonate now feeding so residue mixes with remaining meconium – greenish-brown colour: 3 or more stools a day =size of £2 coin
• Wet nappies 3 or more/daily and getting heavier

Question 30

What is the colour and makeup of poo on day 4-5 and how many wet nappies should there be?

Answer 30

Stools become loose, inoffensive, acidic and bright yellow* 3 or more stools a day as lactation is establishing
* Wet nappies 5 or more/daily and heavy

Question 31

What is the colour and makeup of poo on day 6 onwards and how many wet nappies should there be?

Answer 31

• Stools still like before but with little seedy particles in it (particularly seedy in BF babies)
• 3 or more a day size of £2 coin
• Wet nappies At least 6 heavy nappies daily

Question 32

When is urine produced from?

Answer 32

10/40 weeks, but regulatory/excretory functions of kidney minimal before birth.

Question 33

Tubular reabsorption capabilities are limited at birth, what does this mean?

Answer 33

Means the neoate is unable to concentrate or dilute urine or compensate for high levels of sodium, potassium of chloride in the blood.

Question 34

What are the percentage of newborns passing urine in the brithing or up to 24 hours after birth?

Answer 34

About 20% of newborns wil pass urine in the birthing room, with 90% voiding within 24 hours.

Question 35

Why does a baby have to achieve thermal stability independently once born?

Answer 35

At birth, the intaurterine heat reservoir and heat exchange through the placenta is lost. They must adapt to this new environment by a process known as non-shivering thermogenesis.

Question 36

What happens if a newborn is allowed to become cold?

Answer 36

Then the brown fat stores wll deplete and the newborn will become hypoxic and hypoglycaemic.

Question 37

What are some newborn difficulties in keeping themselves warm?

Answer 37

• Large surface area to body mass ratio.
• Thin layer of insulating subcutaneous fat.
• Immature neonatal skin.
• Immature central nervous system - reduced ability to vasoconstrict/dilate.
• Limited metabolic substrates (factors which break down food) to use for heat production.
• Limited capacity to produce heat through shivering, activity, &movement

Question 38

What ius a clinically accepted temperature range for babies?

Answer 38

36.5 degrees-37.5 degrees c

Question 39

Why can core temperature be unstable in a babies first week of life?

Answer 39

As the heat-regualting centre in the hypothalamus and medulla oblongata adapt to extrauterine environment.

Question 40

What can heat be lost through?

Answer 40

• Evaporation: heat loss through wet skin and towels
• Conduction: coming into contact with cold items and surfaces
• Convection: draughts from open windows and doors
• Radiation: heat being drawn to colder objects (cold wall

Question 41

What is a predictable newborn behavioural changes following birth up to 6hrs?

Answer 41

• 0-1 hrs – Alert & active, may actively seek the breast
• 2-3 hrs – Period of inactivity, may be sleepy & uninterested in feeding
• 4-6 hrs – Second period of reactivity

Question 42

As a midwife how can we care during the transition to extrauterine life?

Answer 42

• Dry baby immediately
• Assess for signs of normal circulation & respiration
• Colour, tone, breathing, heart rate, temperature
• Encourage uninterrupted skin to skin
• Cover with warm, dry towel/blanket
• Encourage early feeding
• Avoid any drafts/cold air/contact with cold surfaces
• Remember, most babies just need time and uninterrupted skin to skin to adapt to life outside the womb. Try to facilitate rather than interfere.

Question 43

What can influence the care in the 4th stage?

Answer 43

• Continuity of carer* Maternal position in labour* Maternal position at birth* Location* IV fluids or oral fluids* Analgesia in labour* Mode of birth* Perineal trauma* Fear and stress* Bleeding

Question 44

What is meant by skin to skin?

Answer 44

the practice where a baby is dried and laid directly onto the mother’s/birthing persons chest.

Question 45

Why is skin to skin contact importunate?

Answer 45

• Calms & relaxes mother/birthing person & baby
• Regulates baby’s heart rate, temperature and breathing
• Stimulates digestion and an interest in feeding
• Colonisation of the baby’s skin with mother’s friendly bacteria
• Stimulates oxytocin production to support breastfeeding and responsive/attuned mothering/parenting

Question 46

What are all maternity units required to do in terms of skin to skin in accordance with BFI standards?

Answer 46

• All mothers have skin to skin contact with their baby at birth, at least until after the first feed & for as long as they wish
• All mothers are encouraged to offer the first feed in skin contact when the baby shows signs to feed
• Mothers and babies who are unable to have skin to skin contact immediately after birth are encouraged to commence skin contact as soon as they are able, whenever or wherever that may be.

Question 47

How does skin to skin increase oxytocin production?

Answer 47

When a baby is placed in skin-to-skin with it’s mother following birth, oxytocin is released. This release of oxytocin causes body temperature to rise, creating a safe place for baby, enabling the beginning of the bonding process. (Cornell, 2020

Question 48

What does oxytocin being released help during breastfeeding?

Answer 48

The oxytocin causes the milk making glands (myo-epithelial cells) to contract, squeezing breastmilk into the milk ducts. (Murray, 2021)

Question 49

How does stress impact oxytocin production?

Answer 49

stress activates the sympathetic nervous system. This causes an inhibiting effect on the hypothalamus, and therefore the pituitary gland, meaning there will be a reduction in the release of oxytocin. (Abele, Plappert and Walter, 2021)

Question 50

Why can the use of skin to skin reduce blood loss?

Answer 50

Can increase the volume of oxytocin naturally produces, reducing blood loss.